As more and more British soldiers are killed and wounded, their commanders are becoming increasingly frustrated by the failure to make a breakthrough in Afghanistan. Morale is being further undermined by the pressures on the defence budget. "They are fighting and dying, while at home they are talking about slashing and cutting," said a well-placed defence source.

Defence officials privately concede that British military planners were hopelessly optimistic when they decided to deploy 3,000 troops in southern Afghanistan in 2006. There are now over 8,000 there, and more are likely to be sent after cuts in the Basra base expected in the first half of next year.

Intelligence on the Taliban, their tactics and strength, was poor. British troops were deployed with inadequate equipment. Though armoured vehicles better able to withstand attacks from rocket-propelled grenades or roadside bombs were later ordered as an "urgent operational requirement" paid for by the Treasury, there are still not enough. The military and politicians alike complain about the slow-moving decision-making process in the Ministry of Defence.

Commanders have also been complaining for years about the shortage of helicopters and aircrew. The MoD recently agreed to deploy British air-sea rescue crews and lease helicopters from private companies. "It is too little, too late," said Colonel Christopher Langton, senior fellow at the International Institute for Strategic Studies.

Frustration at the perceived failure of other Nato countries to pull their weight prompted Des Browne, the defence secretary, recently to deliver a remarkably strong attack on the alliance's failings. There was "far too big a mismatch between our aspirations and what we actually deliver," he told an international security conference in Rome. He will host a meeting of Nato defence ministers in London next month, where Afghanistan will be high on the agenda.

In recent weeks, British soldiers have been killed by roadside bombs, a suicide bomber, and gunfire. The Taliban have not shifted their tactics so much as used the weapons at their disposal with more confidence and audacity, Langton suggested. "It seems the Taliban - the insurgency - are prepared to carry out more frontal kinds of operations," he said, referring to the recent attack on a jail in Kandahar and Tuesday's ambush and suicide bomber attacks on French troops and a US base in Khost. What was worrying, he observed, is the intelligence the Taliban had gathered about foreign troop movements.

By the end of the summer, Langton added, it may be possible to see if the Taliban had established sufficient presence on the Afghan side of the mountains bordering Pakistan to enable them to mount attacks through the winter.

The frustration is reflected in this comment from a very senior British army source. "The past two years," he said, "have achieved a stalemate."

For years, British commanders have been emphasising that there is no military solution to the problem. Yet there is still no effective international civil aid and construction programme, despite billions of dollars of foreign aid delivered or promised, they point out.

"The military alone has always been insufficient to counter an insurgency, which remains essentially a political activity," said Brigadier Ian Dale, a serving British officer, in the latest issue of the UK's Defence Academy's review. "A military coalition is a cumbersome weapon to use in a transnational counter-insurgency campaign and rudderless without a unified political coalition."

British soldiers are frequently attacked in their bases. They are even more exposed on scouting or "hearts and minds" patrols. They know many weapons used by their enemy are paid for by the opium poppy crop which surrounds them, but which they cannot destroy. If they do, farmers will accuse them of taking their livelihood - not the best way to make friends.